Ab initio many-body effects in TiSe₂: A possible excitonic insulator scenario from GW band-shape renormalization
-
Cazzaniga, M.
Università degli Studi di Milano, Physics Department, Milano, Italy - European Theoretical Spectroscopy Facility (ETSF)
-
Cercellier, H.
Institut Néel, CNRS and UJF, Grenoble, France
-
Holzmann, M.
LPTMC, CNRS and UPMC, Paris and LPMMC, CNRS and UJF, Grenoble, France - European Theoretical Spectroscopy Facility (ETSF)
-
Monney, Claude
Synchrotron Radiation and Nanotechnology Department, Paul Scherrer Institut, Villigen, Switzerland
-
Aebi, Philipp
Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, Switzerland
-
Onida, Giovanni
Università degli Studi di Milano, Physics Department, Milano, Italy - European Theoretical Spectroscopy Facility (ETSF)
-
Olevano, V.
Institut Néel, CNRS and UJF, Grenoble, France - European Theoretical Spectroscopy Facility (ETSF)
Show more…
Published in:
- Physical Review B - Condensed matter and materials physics. - 2012, vol. 85, no. 19, p. 195111
English
We present both theoretical ab-initio results within the Hedin's GW approximation and experimental angle-resolved photoemission and scanning tunneling spectroscopy measurements on TiSe₂. With respect to the density-functional Kohn-Sham metallic picture, the many-body GW self-energy leads to a ≈0.2-eV band-gap insulator consistent with our STS spectra at 5 K. The highest valence and the lowest conduction bands are strongly renormalized, with a loss of k² parabolic dispersion toward a k⁴ shape. In particular, GW moves the top of valence moved toward a circle of points away from Γ, arising in a Mexican hat shape commonly associated with an excitonic insulator. Our calculations are in good agreement with experiment.
-
Faculty
- Faculté des sciences et de médecine
-
Department
- Département de Physique
-
Language
-
-
Classification
-
Physics
-
License
-
License undefined
-
Identifiers
-
-
Persistent URL
-
https://folia.unifr.ch/unifr/documents/302507
Statistics
Document views: 48
File downloads: